Stretcher.



J. LEVYMAURIGB & R. E. A. POYART.

. STRETGHER.

APPLICATION FILED JAN. 30, 1911.

Patented Feb. 6, 1912.

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JULES LEVY-MAURICE AND REN REDERC AUGUSTE-N IO'T'Z'AH'. Ol? lzAiFl'ii., FRANCE.

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' Speettaatien of Letters Patent.

Application filed J'anrary QG, 19N.. Serial No. 505.5%.

that elass ot such stretehers as are used tortightening the stays ot aerial vessels.

lilith aerial vessels it isl found in prae` tiee that owing to the continual vibrations, tremors and. shocks` there is a Aconstant risk ot the aeei'dental loosening' or unserewing` of sneli stretehers, and the present invention refers to a'eonstruetion by means ol which sueh risk may be entirely obviated.

)recording to this invention, taking` as an example the oase of a stretcher or junction tor uniting' two stays, we provide the ordinary sleeve or body portion ot' the stretcher at eaeh end with the ordinary oppositely direeted internal screw threads. rlhe ordinary rods carrying' eyes or 'the like are provided with suitable threads oorrespoi'idinl;` with theseI internal screw threads. l'tlaeh end oli the body of the stretcher is externally screw threaded such threads extending' in the reverse direction to the internal thread and the ordinary screw thread on the rod. rlhe rod is further provided in addition to the ordinary or normal thread with a suppleinentai'y serew thi' rad of the same pitch and diret-.tion aS the reverse screw thread on the outside of the body of the stretcher. .l`inally. we provide tor eaeh end a nut wliieli is tarnished with two internally serew threaded portions ot? ditlerent diameters, one, ol whieli is adapted to engage. with the external thread at the end ot the body of the streteher and the other with the Corresponding' thread on the rod. .The second thread in the rod is iireterably so formed that ity ditlers from the normal thread as to the absolute value ot the i'iiteh but only 'to a eoinparatively sinall extent and it is preferably niade shallow so that the normal thread is very little out away and the rod upon which the thread is provided is not ovalized.

with ln order that our invention may be better understood we will now proceed to describe the saine more `tully with reference to the areonipanying drawing. which illustrates merely by 'ay ot example, one method o'tearnvin'g ont the invention as applied to a stretelier or eonneetion with'two endsv or branches.

vFigure l shows the stretcher partly in see tion and partly in elevation. Fig. 2 shows one of the screw threaded rods in elevation. Fig. 3 is a section of the correspondinginit.

a is the body or sleeve portion oit the stretehei"7 the ends ci and L2 of which; are: provided with the ordinary internal r1gl'it-' handed and left-handed sert-wy threads a3.

o and b2 are the eorresponding screwthreaded rods. These rods are. provided, in addition to the ordinary serew threads 3, reverse serew threatfls 1 which are less deeply eut than the said screw threads t1* and which ditlei.- slightly in Vpitch from thel saine. Owing' to the variation ol the pitehes. the. points otE intersection of the threads 113 and o do not eoine upon two straight lines extendingr longitudinally with respeetto the rod, butl traee out, regular heliees extendingr along'l the rod as shown elearly in the drawing.

5" and 72 are a pair ot nuts eorrespoiiding to the ends ii and 0.2. .llaeh of these nuts is internall)y screw threaded with threads c and n ot' two ditl'erent diameters, but ol the saine piteh as the piteh ot the reverse threads ati the ends et the bod7 u. so that' eat-.h ot the aforesaid nuts can be screwed with the portion e screwing upon the rod to which it belongs and with the screw threaded portion e screwing' upon the eirtreinity ot the eorresponding;` end ot' the body o ot' the stretcher.

ln use, the screw threaded rods E and t5 beine removed from the body a, the nuts e and et are serewed on to them. The rods Z3 and b2 are then screwed into the body a and the tightening;- is e'tieeted in the ordinary way by turning' the body. The. nuts c and c2 are now screwed down so that; they engage willi the. eorrespondinf.,r threads on the ends ri" and a2 and the nuts are then locked or Hxed iii position. tter this operation the whole device is absolutely locked as will be easily understood7 :lfor the nuts can only unserew when the rods are fixed relatively to the body.

What We claim and desire to secure by Letters Patent of the United States of America is A Stretcher comprising an internally screw threaded sleeve, a rod in connection with the part to be stretched provided with a screw thread corresponding' to the thread in the sleeve7 a screw thread cut on the outside of and at the end of the sleeve, such screw thread being eppositely 4directed and of slightly different pitch from the thread on'the inside of the sleeve and on the rod,

another and seeondarythread eut on the rod and corresponding in direction and pitch with the thread on the outside of the sleeve, and a nut provided with two internal screw threaded portions of diliierent dialneter but corresponding in direction and pitch with the secondary thread on the rod and with the external thread on the sleeve suhstantially as set forth.

In testimony whereof, we atlix our sig natures, in presence of tivo witnesses.

JULES LEVY-MAURlCE. RENE FREDERIC AUGUSTIN lOYAlt'l. ritnesses DEAN B. MASON, PAUL BLUM. 

